US4484470A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for determining characteristics of clay-bearing formations
Assignee: Western Atlas International Inc
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Filing: 1983-01-05
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Granted: 1984-11-27
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Expires: 2003-01-05
Abstract
Abstract The volume of clay within earth formations is determined throughout the vertical extent of a borehole using measurements of the natural gamma rays emitted from these formations comprised substantially entirely of clay. The clay volume determination is used for evaluating the volume of potassium oxide present in the formations. The percent of expandable layers present within the formations is determined, as a direct indicator of potential clay swelling difficulties and thus sensitivity to formation damage sensitivity, based on an extropolated and normalized potassium oxide volume. The percent expandable layers determination is used for determining the cation exchange capacity of the formations.
Inventors
- 👤 Walter H. Fertl
- 👤 Naum Ruhovets
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:00
CPC Classifications
G; G01; G01V; G01V11/00; E; E21; E21B; E21B49/00
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
57 words
A method of determining characteristics of earth formations, comprising the steps of: determining the volume of clay contained in said earth formations; determining a first property of said formations functionally related to said volume of clay; and determining a second property of said formations in response to said first property, said second property indicating potential clay swelling.
Claim 2
Independent Claim
57 words
A method of determining characteristics of earth formations, comprising the steps of: determining the volume of clay contained in said earth formations; determining a first property of said formations functionally related to said volume of clay; and determining a second property of said formations in response to said first property, said second property indicating potential clay swelling.
Claim 3
Dependent Claim
43 words
The method according to claim 1 wherein the step of determining the volume of clay comprises the steps of: deriving natural gamma ray spectral data from said formations; and determining said volume of clay in response to said natural gamma ray spectral data.
Claim 4
Dependent Claim
52 words
The method according to claim 1 wherein the step of determining a first property comprises the steps of: determining the volume of potassium oxide of said earth formations; and determining in response to said volume of potassium oxide an estimated volume of potassium oxide in an environment composed essentially entirely of clay.
Claim 5
Dependent Claim
22 words
The method according to claim 3 further comprising the step of correcting said volume of potassium oxide for casing and hole size.
Claim 6
Independent Claim
80 words
A method of determining characteristics of earth formations, comprising the steps of: determining the volume of clay contained in said earth formations; determining a first property of said formations functionally related to said volume of clay; and determining a second property of said formations functionally related to said first property, said second property indicating potential clay swelling wherein the step of determining a second property comprises the step of determining the percent of expandable clay layers present in said formations.
Claim 7
Independent Claim
80 words
A method of determining characteristics of earth formations, comprising the steps of: determining the volume of clay contained in said earth formations; determining a first property of said formations functionally related to said volume of clay; and determining a second property of said formations functionally related to said first property, said second property indicating potential clay swelling wherein the step of determining a second property comprises the step of determining the percent of expandable clay layers present in said formations.
Claim 8
Independent Claim
83 words
A method of determining characteristics of earth formations, comprising the steps of determining the volume of clay contained in said earth formations; determining a first property of said formations functionally related to said volume of clay; determining a second property of said formations functionally related to said first property, said second property indicating potential clay swelling; and determining a third property functionally related to said second property and said volume of clay, said third property indicating the cation exchange capacity of said formations.
Claim 9
Independent Claim
83 words
A method of determining characteristics of earth formations, comprising the steps of determining the volume of clay contained in said earth formations; determining a first property of said formations functionally related to said volume of clay; determining a second property of said formations functionally related to said first property, said second property indicating potential clay swelling; and determining a third property functionally related to said second property and said volume of clay, said third property indicating the cation exchange capacity of said formations.
Claim 10
Dependent Claim
31 words
The method according to claim 5 further comprising the step of determining the cation exchange capacity unit per pore volume (Qv) of said formations in functional relation to said third property.
Claim 11
Dependent Claim
26 words
The method according to claim 7 further comprising the step of determining the water saturation of said formations in response to said Qv of said formations.
Claim 12
Independent Claim
114 words
A method of determining characteristics of clay-bearing earth formations, comprising the steps of: generating electrical signals functionally related to the energy and frequency of detected radiations; determining in response to at least a portion of said electrical signals the volume of clay content of said formations; determining in response to at least a portion of said electrical signals a first property of said formations; determining in response to said first property a second property of said formations, said second property indicating the percent of expandable clay layers of said formations; and determining the cation exchange capacity of said formations, said determination functionally related to said volume of clay and said percent of clay layers.
Claim 13
Independent Claim
114 words
A method of determining characteristics of clay-bearing earth formations, comprising the steps of: generating electrical signals functionally related to the energy and frequency of detected radiations; determining in response to at least a portion of said electrical signals the volume of clay content of said formations; determining in response to at least a portion of said electrical signals a first property of said formations; determining in response to said first property a second property of said formations, said second property indicating the percent of expandable clay layers of said formations; and determining the cation exchange capacity of said formations, said determination functionally related to said volume of clay and said percent of clay layers.
Claim 14
Dependent Claim
41 words
The method of claim 9 wherein the step of generating electrical signals comprises the steps of: detecting natural gamma radiations emanating from said formations; and generating electrical signals functionally related potassium, thorium and total gamma ray counts of said detected radiations.
Claim 15
Dependent Claim
34 words
The method of claim 10 wherein the step of determining the volume of clay comprises the steps of: determining a potassium-thorium product index; and determining said volume of clay in response to said index.
Claim 16
Dependent Claim
31 words
The method of claim 10 wherein the step of determining the volume of clay comprises the step of determining the volume of clay in response to the total gamma ray counts.
Claim 17
Dependent Claim
43 words
The method of claim 10 wherein the step of determining the volume of clay comprises the steps of: determining a potassium-thorium product index; and determining said volume of clay in response to a combination of said index and said total gamma ray counts.
Claim 18
Dependent Claim
26 words
The method of claim 10 wherein the step of determining a first property includes the step of determining the volume of potassium oxide of said formations.
Claim 19
Dependent Claim
48 words
The method of claim 14 wherein the step of determining the volume of potassium oxide includes the step of determining said volume of potassium oxide in an environment composed essentially entirely of clay, said environment having a composition functionally equivalent of said volume of clay of said formations.
Claim 20
Dependent Claim
22 words
The method according to claim 14 further comprising the step of correcting said volume of potassium oxide for casing and hole size.
Claim 21
Independent Claim
174 words
A method of well logging, comprising the steps of: traversing a borehole with a natural gamma ray spectral logging instrument; detecting natural gamma radiation occurring in the formations surrounding said borehole; generating electrical signals functionally related to the energy and frequency of said detected radiation corresponding to potassium, thorium and total gamma ray counts; determining the volume of clay within said formations in response to at least a portion of said electrical signals; determining the volume of potassium oxide content of said formations in response to said electrical signal corresponding to potassium; correcting said volume of potassium oxide for casing and hole size; determining in response to said corrected volume of potassium oxide the potassium oxide content for an environment composed essentially entirely of clay having a composition functionally equivalent to said volume of clay of said formations; determining the percent of expandable clay layers within said formation in response to said potassium oxide content; and determining the cation exchange capacity in response to said percent of expandable layers and said volume of clay.
Claim 22
Independent Claim
174 words
A method of well logging, comprising the steps of: traversing a borehole with a natural gamma ray spectral logging instrument; detecting natural gamma radiation occurring in the formations surrounding said borehole; generating electrical signals functionally related to the energy and frequency of said detected radiation corresponding to potassium, thorium and total gamma ray counts; determining the volume of clay within said formations in response to at least a portion of said electrical signals; determining the volume of potassium oxide content of said formations in response to said electrical signal corresponding to potassium; correcting said volume of potassium oxide for casing and hole size; determining in response to said corrected volume of potassium oxide the potassium oxide content for an environment composed essentially entirely of clay having a composition functionally equivalent to said volume of clay of said formations; determining the percent of expandable clay layers within said formation in response to said potassium oxide content; and determining the cation exchange capacity in response to said percent of expandable layers and said volume of clay.
Claim 23
Dependent Claim
30 words
The method of claim 17 further comprising the step of determining the cation exchange capacity unit per pore volume (Qv) of said formations in response to said cation exchange capacity.
Claim 24
Dependent Claim
25 words
The method of claim 18 further comprising the step of determining the water saturation of said formations in response to said Qv of said formations.
Claim 25
Dependent Claim
24 words
The method of claim 17 further comprising the step of normalizing said electrical signal corresponding to potassium in response to said potassium oxide content.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-11-27 | 1988-05-28 | 1988-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-27 | 1992-05-28 | 1992-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-27 | 1996-05-28 | 1996-11-27 | $7700.00 | Window Closed / Lapsed |